Page:The Scientific Monthly vol. 3.djvu/429

 EXPLOSION CRATERS 4»3

One of these craiera in tite plain 2^ miles northeast of Tinaja de loa Fapagoa iras named Sykee Crater by Horoaday. According to Lumboltz it had been visited by 3r. Y. Bonltlas of Nogales in 1883. Sykee, who was geographer of Homaday'a expedition, found that the

depth of the crater is 760 feet, its diameter at bottom 1,400 feet, and the bottom ie 150 feet above sea level. A view of this great hole is given in Pig. 7. Lumholtz states that the rim is 130 feet high where

��he crossed it. It evidently consists of ejecta and Homaday states that in places the apex of the rim is "sandstone formed by the fusing of masses of volcanic sand nnder the influence of intense heat" and regards the material as having been thrown out of the crater.

Another great crater in the same vicinity has been named Mac- Dongal Crater by Homaday. It is in the lava plain a short distance southwest of the foot of Homaday Mountains. A view of this hole, from a photograph kindly supplied by Mr. Charles Sheldon, is given in Fig. 8. The diameter of the bottom is 3,600 feet and depth below

��Pia. 8. MicDoDOAi. Cbatbii, Looeino Bodtbwksi fboh Top or Hobnadaz Hodn- TAiHB. SONOiu, Mexico. Photo bj C. SbeldoQ, iei6.

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